Khloe Kardashian opened up about sister Kim's struggle to get pregnant [Khloe Kardashian/Instagram]

"So Kim is super nervous and anxious during this waiting period. Of course she wants to know is she or is she not having another baby."

Speaking about the wait to find out whether she was having another child, Kim admitted the process – which had been a ‘year in the making’ – was ‘frustrating’.

"This is the craziest waiting game," she told Khloé. "It’s so frustrating. It’s really nerve-wracking because you know it’s only a 60 percent chance it’ll take. One didn’t work for me. I tried it and I lost one of them.

Kanye West and Kim Kardashian are parents to son Saint and daughter North [Getty]

However, Kim also admitted having a surrogate carry her third child was ‘weird’, explaining she didn’t know how to celebrate or what to do next.

Kim Kardashian and Kanye West have struggled to have a third child[Getty]

"It’s kind of weird when it’s not you, so I don’t know whether I should start eating donuts and celebrate like I would like old times or just go to the gym," she confessed to sister Kourtney Kardashian.

"I’m totally gonna forget and then a month before I’m gonna be like holy s**t, we need to get a nursery."

"It is frustrating to not be able to do it on your own," she added. "It is a weird dynamic.

Kim Kardashian admitted she was frustrated at not being to carry her third child[Getty]

"Like, I go to all the doctor's appointments and I try to be really present, but when you're not carrying it yourself it is such a fine balance of how much you're going to be in their lives.

"Of course I want to know every last detail that's going on with my baby and that's super frustrating, but I really trust my surrogate and I don't want to be that person that's trying to control her every move.

"It's going to be a long hard process but I'm going to take it one day at a time and hopefully it just gets easier."